COMPOSITIONS CONTAINING POLYMERIC CARBODIIMIDE, EPOXY AND POLYESTER-BASED POLYMERS, THEIR PRODUCTION AND USE

Description

[0001] The present invention relates to compositions containing polymeric carbodiimide, epoxy and polyester-based polymers, their preparation and use for hydrolysis protection.

[0002] Various carbodiimides have proven themselves in many applications, e.g. as hydrolysis inhibitors for thermoplastics, ester-based polyols, polyurethanes, triglycerides and lubricating oils, etc. However, they have the disadvantage of emitting gases that are harmful to health and are expensive and complex to produce.

[0003] Epoxies are cheaper to produce, but have the disadvantage that, even at very high concentrations, they do not achieve the hydrolysis-stabilizing effect of carbodiimides. They act merely as acid scavengers and provide only insufficient long-term stabilization at elevated temperatures. These agents are particularly ineffective as hydrolysis stabilizers in very demanding applications under conditions such as high humidity and temperature, since ester-based plastics are generally processed at temperatures above 200°C. DE 10349168 A1 describes a hydrolysis stabilizer made from epoxidized fatty acid esters and glycerides, as well as a mixture of these with a monomeric carbodiimide. The stabilizers described here act as acid scavengers in oils.However, under the above-mentioned conditions, these show little or no effect on long-term stability against hydrolysis when processing ester-based thermoplastics. Furthermore, the use of monomeric carbodiimides leads to increased emissions of toxic gases.

[0004] EP 1 710 277 A1 discloses hydrolysis-resistant polyester elastomer compositions comprising a polymeric aromatic carbodiimide, an alicyclic epoxy and a thermoplastic polyester elastomer.

[0005] The object of the present invention was therefore to provide new cost-effective compositions which are hydrolysis-resistant, can be produced cost-effectively and show reduced emissions.

[0006] Surprisingly, it has now been found that the above-mentioned object can be achieved if a combination of at least one polymeric aromatic carbodiimide, at least one epoxide having at least 2 epoxide groups and at least one polyester-based polymer, in particular a polyalkylene terephthalate or polylactide, is used.

[0007] The present invention therefore relates to compositions containing (a) at least one polymeric aromatic carbodiimide of the formula (I) R 1< -R 2< -(-N=C=NR 2< -) m -R 1< (I), in which m corresponds to an integer from 2 to 500, preferably 3 to 20, very particularly preferably 4 to 10, R 2< represents C 1 -C 12 -alkyl-substituted arylenes, C 7 -C 18 -alkylaryl-substituted arylenes, and arylene, preferably R 6< , R 7< and R 8< each independently represents methyl or ethyl, wherein each benzene ring has only one methyl group and n = 1 to 10 and R 1< is -NCO, -NCNR 3< -NHCONHR 3< , -NHCONR 3< R 4< or -NHCOOR 5<, wherein R 3< and R 4< are the same or different and represent a C 1 -C 12 alkyl, C 6 -C 12 cycloalkyl, C 7 -C 18 aralkyl or aryl radical and R 5< corresponds to a C 1 -C 22 alkyl, C 6 -C 12 cycloalkyl, C 6 -C 18 aryl or C 7 -C 18 aralkyl radical, as well as an unsaturated alkyl radical having 2 - 22 carbon atoms or an alkoxypolyoxyalkylene radical, (b) at least one epoxy of the following formula (III) and / or at least one epoxy of the following formula (IV). (c) at least one thermoplastic polyester-based polymer.

[0008] The term arylene includes in particular phenylene, naphthylene, anthrylene and / or phenanthrylene residues, preferably phenylene residues.

[0009] The polymeric aromatic carbodiimides a) are preferably compounds of the formula (II), in which R 1< is selected from the group -NCO, -NHCONHR 3< , -NHCONR 3< R 4< or -NHCOOR 5< , where R 3< and R 4< are identical or different and represent a C 1 -C 12 alkyl, C 6 -C 12 cycloalkyl, C 7 -C 18 aralkyl radical or aryl radical, R 5< corresponds to a C 1 -C 22 alkyl, C 6 -C 12 cycloalkyl, C 6 -C 18 aryl or C 7 -C 18 aralkyl radical, and an unsaturated alkyl radical having 2 - 22 carbon atoms, preferably 12 - 20, particularly preferably 16 - 18 carbon atoms, or an alkoxypolyoxyalkylene radical, and R 6< , R 7< and R 8< each independently represent methyl or ethyl where each benzene ring has only one methyl group and n = 1 to 10.

[0010] The carbodiimide content (NCN content, measured by titration with oxalic acid) of the carbodiimides of formula (II) used according to the invention is preferably 2-14 wt.%, more preferably 4-13 wt.%, particularly preferably 6-12 wt.%.

[0011] The carbodiimides of formula (II) used according to the invention furthermore preferably have average molecular weights (Mw) of 1000 - 5000 g / mol, preferably 1500 - 4000 g / mol, particularly preferably 2000 - 3000 g / mol, determined by GPC viscometry.

[0012] Furthermore, carbodiimides of the formula (II) are preferred which have a polydispersity D = Mw / Mn of 1.2 - 2.2, particularly preferably of 1.4 - 1.8.

[0013] The carbodiimides are preferably commercially available compounds, such as the polymeric carbodiimides known as Stabaxol® from Lanxess Deutschland GmbH. However, they can also be produced, for example, using the processes described in EP14191710.4.

[0014] Component b) preferably has a total of at least two epoxide groups per molecule, with at least one epoxide group preferably being terminal.

[0015] The production epoxidized compounds is also known to the person skilled in the art. Preferred epoxidized compounds are polyglycidyl or poly(beta-methylglycidyl) ethers, preferably obtainable by reacting a compound having at least two free alcoholic or phenolic hydroxy groups and / or by reacting phenolic hydroxy groups with a substituted epichlorohydrin.

[0016] Preferred polyglycidyl or poly(beta-methylglycidyl) ethers are derived from acyclic alcohols, in particular ethylene glycol, diethylene glycol and higher poly(oxyethylene) glycols, propane-1,2-diol or poly(oxypropylene) glycols, propane-1,3-diol, butane-1,4-diol, poly(oxytetramethylene) glycols, pentane-1,5-diol, hexane-1,6-diol, hexane-2,4,6-triol, glycerol, 1,1,1-trimethylpropane, bistrimethylolpropane, pentaerythritol, sorbitol and polyepichlorohydrins.

[0017] Alternatively preferred polyglycidyl or poly(beta-methylglycidyl) ethers are derived from cycloaliphatic alcohols, in particular 1,3- or 1,4-dihydroxycyclohexane, bis(4-hydroxycyclohexyl)methane, 2,2-bis(4-hydroxycyclohexyl)propane or 1,1-bis(hydroxymethyl)cyclohex-3-ene, or they have aromatic nuclei based on N,N-bis-8,2-hydroxyethyl)aniline or p,p'-bis(2-hydroxyethylamino)diphenylmethane.

[0018] Preferred epoxidized compounds are also based on mononuclear phenols and polynuclear phenols.

[0019] Preferred mononuclear phenols are resorcinol or hydroquinone.

[0020] Preferred polynuclear phenols are bis(4hydroxyphenyl)methane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane or 4,4'-dihydroxydiphenylsulfone.

[0021] Preferred condensation products of phenols with formaldehyde are phenol novolaks.

[0022] Preferred aromatic epoxy compounds have two terminal epoxy functions.

[0023] The preferred aromatic epoxy compound with two terminal epoxy functions is an oligomeric reaction product of bisphenol A with epichlorohydrin with an average molecular weight according to EN ISO 10927 in the range of 900 to 1200 g / mol and an epoxy index (according to ISO 3001) in the range of 450 to 600 grams per equivalent. Component c) is particularly preferably an oligomeric reaction product of bisphenol A with epichlorohydrin of the formula (III), with a from 0 to 10, preferably with a from 1 to 8, particularly preferably with a from 1 to 6, particularly preferably in the range from 2 to 3, where a corresponds to the average number.

[0024] Preferably, components c) are prepared by a process according to US2002 / 0128428 A1 and then have, according to EN ISO 10927, an average molecular weight in the range from 900 to 1200 g / mol (corresponds to an a in the range from 2 to 3 in formula (III)) and an epoxy index (according to ISO 3001) in the range from 450 to 600 grams per equivalent.

[0025] An epoxy compound to be used according to the invention preferably has a Mettler softening point according to DIN 51920 in the range from 0 to 150°C, particularly preferably from 50°C to 120°C, most preferably from 60°C to 110°C, and especially from 75°C to 95°C. The Mettler softening point is the temperature at which the sample flows out of a cylindrical nipple with an outlet opening of 6.35 mm diameter, interrupting a light barrier located 19 mm below. For this purpose, the sample is heated in air under constant conditions.

[0026] Epoxy compounds to be used preferably have an average epoxy equivalent weight (EEW, grams of resin containing one mole of epoxide-bound oxygen) via titration according to DIN 16945 in the range from 160 to 2000 g / eq, preferably in the range from 250 to 1200 g / eq, particularly preferably in the range from 350 to 1000 g / eq and especially preferably in the range from 450 to 800 g / eq.

[0027] Particularly preferably, a poly(bisphenol A-co-epichlorohydrin) [CAS No. 25068-38-6] is used as component b), preferably with a number-average molecular weight (M n ) in the range from 600 to 1800 g / mol, which can be determined by MALDI-TOF mass spectrometry using matrix-assisted laser desorption / ionization time-of-flight mass spectrometry in accordance with EN ISO 10927, for example available as Epilox ®< from Leuna Harze GmbH, Leuna.

[0028] Further preferred epoxy compounds with at least 2 epoxy functions are compounds from the series of epoxides, commercially available under the name Joncryl ®< from BASF AG such as Joncryl ®< 4368 which contain the following units in any combination and

[0029] With R 9< , R 10< = independently of one another H, C 1 - C 8 -alkyl, R 11< = independently of one another C 1 -C 8 -alkyl, x, y = 1 - 20, z = 2 - 20 , where end groups R* stand for H, C 1 -C 8 -alkyl.

[0030] Preferably, the epoxide corresponds to the formula (IV)

[0031] With R 9< , R 10< = independently of one another H, C 1- C 8 -alkyl, R 11< = independently of one another C 1 -C 8 -alkyl, x, y = 1 - 20, z = 2 - 20 , where the end groups R* are H, C 1 -C 8 -alkyl.

[0032] The thermoplastic polyester-based polymers c) are preferably poly-C 1 -C 8 -alkyl terephthalates, particularly preferably polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), as well as copolyesters, thermoplastic polyester elastomers (TPE E), ethylene vinyl acetate (EVA), polylactic acid (PLA) and / or PLA derivatives, polybutylene succinates (PBS), polyhydroxyalkanoates (PHA), as well as various blends thereof.

[0033] Polylactides (PLA) are particularly preferred.

[0034] In a preferred embodiment of the present invention, the composition according to the invention contains a) 0.2 to 2 wt.%, preferably 0.4 to 1.5 wt.%, particularly preferably 0.5 to 1.0 wt.%; b) 0.05 to 4 wt.%, preferably 0.1 to 2 wt.%, particularly preferably 0.5 to 1.5 wt.%; c) 94 to 99.75 wt.%, preferably 96.5 to 99.5 wt.%, particularly preferably 97.5 to 99.0 wt.%.

[0035] In a further preferred embodiment of the present invention, the compositions do not contain any further components besides components a), b) and c), the sum of the proportions of a), b) and c) being 100% by weight.

[0036] The present invention further provides a process for producing the composition, according to which components a) and b) are mixed into at least one thermoplastic polyester-based polymer c). Extruders or kneaders are preferred, particularly extruders. These are commercially available stirring and mixing units.

[0037] In a preferred embodiment of the present invention, the mixing of components a), b) and c) takes place at temperatures of 150 to 300°C.

[0038] In a further embodiment of the process according to the invention, further additives, preferably nucleating agents, reinforcing fibers, impact modifiers, flow improvers and / or UV stabilizers are mixed into the mixture of components a), b) and c).

[0039] The present invention further relates to a process for producing hydrolysis-stable products by processing compositions comprising components a), b) and c) in at least one mixing unit, preferably a compounder, into molding compositions and subjecting these to further processing, preferably an injection molding process or extrusion, for producing products.

[0040] Processes according to the invention for producing products by extrusion or injection molding are carried out at melting temperatures in the range from 160 to 330°C, preferably in the range from 190 to 300°C and optionally additionally at pressures of not more than 2500 bar, preferably at pressures of not more than 2000 bar, particularly preferably at pressures of not more than 1500 bar and very particularly preferably at pressures of not more than 750 bar.

[0041] Extrusion is primarily divided into profile extrusion and sequential coextrusion. In sequential coextrusion, two different materials are extruded one after the other in alternating sequence. This creates a preform with a different material composition in sections along the extrusion direction. By selecting the appropriate material, specific sections of the product can be equipped with specifically required properties, for example, for products with soft ends and a hard middle section or integrated soft bellows sections. ( Thielen, Hartwig, Gust, "Blow molding of hollow plastic bodies", Carl Hanser Verlag, Munich 2006, pages 127-129 ).

[0042] The injection molding process is characterized by the fact that the raw material, preferably in granular form, is melted (plasticized) in a heated cylindrical cavity and injected under pressure into a temperature-controlled cavity as an injection molding compound. Compositions according to the invention are used as the raw material, which have preferably already been compounded into a molding compound, which in turn has preferably been processed into granules. After the molding compound injected into the temperature-controlled cavity has cooled (solidified), the injection-molded part is removed from the mold.

[0043] In contrast to injection molding, extrusion uses a continuously formed plastic strand, here made of a molding compound according to the invention, in the extruder, whereby the extruder is a machine for the production of thermoplastic molded parts / products. Single-screw extruders and twin-screw extruders as well as the respective subgroups of conventional single-screw extruders, conveying-effective single-screw extruders, counter-rotating twin-screw extruders and co-rotating twin-screw extruders.

[0044] Extrusion lines typically consist of an extruder, tool, downstream equipment, and extrusion blow molding. Extrusion lines for producing profiles typically consist of an extruder, profile tool, calibration, cooling section, caterpillar and roller take-off, cutting device, and tilting chute. Extrusion lines for producing films typically consist of an extruder, cooling section, stretching, and roller take-off.

[0045] Products obtainable according to the invention are preferably materials that are exposed to aqueous media, atmospheric humidity or splash water.

[0046] Such hydrolysis-stabilized products are found particularly in motor vehicles, in the electronics, telecommunications, information technology, and computer industries, as well as in the household, sports, medicine, and entertainment industries. In a preferred variant, the compositions according to the invention are used to produce hydrolysis-stable films, e.g., for packaging or solar cells.

[0047] The present invention also relates to the use of the composition according to the invention for producing products by extrusion, preferably for packaging or solar cells.

[0048] The scope of the invention encompasses all of the above and below general or preferred ranges of radical definitions, indices, parameters and explanations among each other, and therefore also between the respective ranges and preferred ranges in any combination.

[0049] The following examples serve to illustrate the invention without limiting it. Examples of implementation: The following were used:

[0050] 10.8 wt.% based on 2,6-diisopropylphenyl isocyanate, available from Lanxess Deutschland GmbH under the name Stabaxol ®< I. 2) Rod B: a polymeric carbodiimide with an NCN content of approx. 11.8 wt.%, D = approx. 1.8 and Mw = 2300 g / mol of the formula (II) with n = approx. 3 - 4, R 6< , R 7< , R 8< each independently represents methyl or ethyl, where each benzene ring has only one methyl group and R 1< = - NHCOOR 5< and R 5< = cyclohexyl. 3) Rod C: An epoxy of formula (III) with n = in the range of 2 - 3 with an epoxy equivalent weight (DIN 16945) of 500 to 700 g / eq and a softening point (Mettler, DIN 51920) between 75 and 90°C. [CAS No. 25068-38-6]. 4) Polyethylene terephthalate (PET) available from Novapet. 5) Polylactic acid (PLA) available from NatureWorks. Hydrolysis protection in polyethylene terephthalate (PET)

[0051] To evaluate the hydrolysis protection effect in PET, the stabilizers used in each example (rods A, B, and C) were dispersed in PET at approximately 280 °C using a Werner & Pfleiderer ZSK 25 laboratory twin-screw extruder prior to the measurement described below. The F3 standard test specimens used to measure tear strength were then produced from the obtained granules on an Arburg Allrounder 320 S 150-500 injection molding machine.

[0052] For the hydrolysis test, these F3 standard test specimens were stored in steam at a temperature of 110°C and their tensile strength was measured in MPa. Hydrolysis protection in polylactic acid (PLA)

[0053] To evaluate the hydrolysis protection effect in PLA, the stabilizers used in each example (rods B and C) were dispersed in PLA at approximately 200 °C using a Werner & Pfleiderer ZSK 25 laboratory twin-screw extruder prior to the measurement described below. The F3 standard test specimens used to measure tear strength were then produced from the obtained granules on an Arburg Allrounder 320 S 150-500 injection molding machine.

[0054] For the hydrolysis test, these F3 standard test specimens were stored in water at a temperature of 65°C and their tensile strength was measured in MPa.

[0055] The quantities of the mixture components and their results are listed in Tables 1 and 2: Table 1: Relative tear strength (%) Example 1 (cf.) PET Example 2 (cf.) PET, 1% rod A Example 3 (cf.) PET, 2% rod C Example 4 (cf.) PET, 4% rod C Example 5 (cf.) PET, 1% rod A, 1.5% rod C 0 days 100 100 100 100 100 1 day 75 86 61 63 86 2 days 40 80 33 40 81 3 days 0 64 0 0 65 4 days 44 47 5 days 30 38 cf. = comparative example from DE 10349168, req. = according to the invention Table 2: Relative tear strength (%) Example 1 (cf.) PET Example 6 (cf.) PET, 1% rod. b Example 7 (required) PET, 1% rod B, 1.5% rod. C 0 days 100 100 100 1 day 75 86 89 2 days 40 83 89 3 days 0 76 87 4 days 60 82 5 days 40 64 6 days 18 54 7 days 0 40 cf. = comparative example, req. = according to the invention Table 3: Relative tear strength (%) Example 8 (cf.) PLA Example 9 (cf.) PLA, 4% rod C Example 10 (cf.) PLA, 0.5% rod B Ex. 11 (required) PLA, 0.5% Rod B, 1.5% Rod C 0 days 100 100 100 100 1 day 94 96 98 98 2 days 62 79 96 97 3 days 22 57 71 97 4 days 0 0 44 97 5 days 0 97 6 days 97 7 days 97 8 days 97 9 days 97 10 days 97 11 days 94 12 days 88 13 days 67 14 days 53 15 days 28 16 days 0 cf. = comparative example from DE 10349168, req. = according to the invention

[0056] The percentages in Tables 1 and 2 correspond to the weight percentages of the corresponding stabilizers.

[0057] The results of the hydrolysis protection tests demonstrate that the epoxides alone have little or no stabilizing effect, but surprisingly, when combined with the polymeric carbodiimides of the invention (e.g., Stab. B), they exhibit a significant positive synergistic effect on hydrolysis stability. In contrast, the combination of monomeric carbodiimides with the epoxides does not lead to such a synergistic effect.

Claims

1. Composition containing (a) at least one polymeric aromatic carbodiimide of formula (I)         R1-R2-(-N=C=N-R2-)m-R1     (I), in which m represents an integer from 2 to 500, preferably 3 to 20, very particularly preferably 4 to 10, R2 = C1-C12-alkyl-substituted arylenes, C7-C18-alkylaryl-substituted arylenes and also arylene, and R1 = -NCO, -NCNR3, -NHCONHR3, -NHCONR3R4 or -NHCOOR5, wherein R3 and R4 are identical or different and represent a C1-C12-alkyl, C6-C12-cycloalkyl, C7-C18-aralkyl or aryl radical and R5 represents a C1-C22-alkyl, C6-C12-cycloalkyl, C6-C18-aryl or C7-C18-aralkyl radical and an unsaturated alkyl radical having 2 - 22 carbon atoms or an alkoxypolyoxyalkylene radical, (b) at least one epoxide of formula (III) where a is 0 to 10, preferably where a is 1 to 8, particularly preferably where a is 1 to 6, very particularly preferably in the range from 2 to 3, wherein a represents the average number and / or of formula (IV) where R9, R10 = H, C1-C8-alkyl, R10 = C1-C8-alkyl, x, y = 1 - 20 and z = 2 - 20, and R* = H, C1-C8-alkyl, (c) at least one thermoplastic polyester-based polymer selected from the group polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), thermoplastic polyester elastomers (TPE E), ethylene vinyl acetate (EVA), polylactic acid (PLA) and / or PLA derivatives, polybutylene succinates (PBS), polyhydroxyalkanoates (PHA), and various blends, thermoplastic polyurethanes, polyurethane elastomers, PU adhesives and PU casting resins.

2. Composition according to Claim 1, characterized in that the polymeric aromatic carbodiimides are compounds of formula (II) where R1 is selected from the group of -NCO, -NHCONHR3, - NHCONR3R4 or -NHCOOR5, where R3 and R4 are identical or different and represent a C1-C12-alkyl, C6-C12-cycloalkyl, C7-C18-aralkyl radical or aryl radical, R5 represents a C1-C22-alkyl, C6-C12-cycloalkyl, C6-C18-aryl or C7-C18-aralkyl radical and an unsaturated alkyl radical having 2 - 22 carbon atoms, preferably 12 - 20, particularly preferably 16 - 18 carbon atoms, or an alkoxypolyoxyalkylene radical and R6, R7 and R8 each independently represent methyl or ethyl, wherein each benzene ring bears only one methyl group and n = 1 to 10.

3. Composition according to either of Claims 1 to 2, characterized in that it comprises a), b) and c) in the following proportions: a) 0.2 - 2% by weight, preferably 0.4 - 1.5% by weight, particularly preferably 0.5 - 1.0% by weight, b) 0.05 - 4% by weight, preferably 0.1 - 2% by weight, particularly preferably 0.5 - 1.5% by weight, c) 94 - 99.75% by weight, preferably 96.5 - 99.5% by weight, particularly preferably 97.5 - 99.0% by weight.

4. Process for producing a composition according to any of Claims 1 to 3, characterized in that the components a), b) are admixed into at least one thermoplastic polyester-based polymer c) .

5. Process for producing a composition according to Claim 4, characterized in that the components a), b) are admixed into at least one thermoplastic polyester-based polymer c) at temperatures of 160 - 330°C.

6. Articles of manufacture, preferably hydrolysis-stable articles of manufacture, obtainable by admixing the compositions according to any of Claims 1 to 3 in at least one mixing assembly, preferably a compounder, and further processing to afford moulding materials in injection moulding processes or by extrusion.

7. Use of the composition according to any of Claims 1 to 3 for producing articles of manufacture by extrusion, preferably for packaging or solar cells.